Latch bolt unit



G. HAGSTROM LATCH BOLT UNIT Jan. 5, 1954 Original Filed Aug. 11, 1950ATTORNEY Patented Jan. 5, 1954 ATCH. OLT

Gotthard Hagstrom, Greenwich, Gonm, assignor d h Safe Padlock a d;Hardware. Qomnan i Lanc ster, Ba, ,1- asrion ofi Be nsy vauia O aapplication August 1.1, 195 Se i l Nu-i 178,897, how Patent No.2,644,7(14; dated July 7, 1953. Divided and this application Februar-i-14, 1952,4Serial No. 271,492

11 Claims. (01. 292 7-163)" This invention relates to. certainimprovements in t h ol unit nd the nature; an objects f he inv ntionwill be readily r co ni d by thos l d i the rts invo ved n: th ght at tht l o ins p anati and detail d de rin t on of the acs mpany s dr w na ilu tiret a what I no elieve to be the p e erred emh di= meri s or mechanca expressions of the nventi n ir m am g va ou ther embod ment m difireatiohs. var atio comb nations and ons r e tions of which the inventionis capablelwithin the broad spirit, and. scope thereof as defined by thela ms hereto; appended:

This. applioationiisfiled as a division of my eon-t se ing applicati nserial. N 1 39.7, filed Au-. u t 1.1 1950. for Door- .Latch Me han m Pant NO, Mi -i3 4, i sued July 7, i953.

he inventionis par cularly ern d; w th h o called tubular latch bolts foinstall ti n and m un in in a m i ad; o b ed p n n formed in a closuresuch, as a door, Such latch bolts usually f r unit wh ch comp ise acase. within which is, housed a spring; loaded latch bolt for projectionto latching position by the biasing; -s on of. its. pr ng loa ing andforret a n t un'latohed; position against, its snring loading, M anism iinc ud d w h n the ase for aetuation to retract, the latch boltwhilethe'association of. such m chan sm and the a h lt i usually such that thebolt nay be depressed to retractedposition independently of theretraoting mechanism,

I is, an obje t at my invention to pr an impro ed d si n andc u truct onof. tubu ar. latch bolt unit. capable of general use with various typesof do r la ch nd 100k m hani m a d e sooalled door look sets formedtherewith.

A other objec is o r v de a tubular at h b unit adaptedfor neral u e asa. plain unit of the p n e a tua ed, type a well as ing ad p e forafiisi n use with various nee a ty es of. do r at-ah mechanisms, such, fr exa mole, the inside door set is l s d in my afore aid patent.

A fur he obj ct to p ov e a de ign nd construction Qf tuhulat latch boltunit which can e readily m nufa tured in quant ty pr duct on at, low o tyet whi h will insu e p siti e. p ci io op ra io oi he un w h a minimumo mai tenan and ruc ural o p rati nal fa lurea under the arious cond ont which. sub jected in o erati n and.

, Another ob ct s o pro ide a u ar case for la ch b.0 2 unit o asonstrustio which has a m nimum of p rts of. character to be read lytamped or formed and. re d ly a curately as sembled for low-costquantity production,

A u t erb ect i to provide such a case de: ig d 5 3 co erative m untingtherein in opera a-tive assembly; the; components. of the. latch, bolt rtraa ns. me hanism for; functioning; of}; such mechanism with minimumfriction. yet withlpreoia n. under ll no mal operatin conditions.

A da ur er o ject. is to. provide.- an improved and s mplifi d: cstituction and assem ly oftu= hula 6 mqunteddatohbolt retracting mecha:nism and of the latch bolt operatively assembled th with.

ith the fore oin and variQus other obi e features and, results in viewwhich will be readily apparent fromlthe following detailed descriptionand explanation, my inventioneonsists in certain novel features i d i nand construction, and in ombinations and suh sombinations of pa delements, all as will be more fully referred to, and spec fiedhereinafteri.

f rr ng to the aoqompanyin drawings. in which similar reierencecharacters refer to corre= no di s parts. throu hout the several:figures thereof:

Fig. 1 is aview in horizontal section through a latch b lt unit of theinvention, in? mounted, in. stalled position in a. door in, operative;association with a door knob operated latch bolt retracting pindl iportiori only of. the. door being shown.

Fi 2 is a view in vertical longitudinal section taken as on th line 2:of'l ie. 1.

Fig. 3 is an exploded View illustratingin per--.. speotive the parts andcomponents; makingeun the latch looltunit of the form of the exampleunit of Figs. 1 and 2, with the parts of the tubularease, the latch boltand the bolt retracting mech-- anism being: shown separated but; in therelative positions thereof to he assumed in assembly.

Fig. 4 is a View in top plan of a portion of the unit, showing partielarly t e m unting of the bearing plate. and. rolibaok in the case.

A presentlynreferred orm and emb d m i a tubular e se latch hoit unitembodying the vari us ieatures of my invention ha been sea looted nd. ssslas here n by W313i of examp in operative installa ion and associat dw h 9 suit bl knob operated. astua n stain-die 0f" any suitable or d sid d or lo k: set but without any intention to limit the use of the latchbolt unit to such door lock set 9; in any other particular set. Referrig t Fi l and 2 of the drawings, a portion of a door 1.3. is iselosed inwhi h a usual mortised or bor d passa e or space is formed which extendsinto the body of the door D. through the outer fir s edge 3; thereof. Atubular latch bolt unit L of the invention is mounted in horizontallydisposed position within the bore 2 in operative association with a doorlock or latch set which includes a spindle S mounted in positionextended transversely through the door D and the latch bolt unit L. Thedoor D is provided with a circular bored opening 4 which extendstransversely through the door across and intersects opening 2 with theaxes of these bores 2 and 4 being perpendicular to each other. It is thebore 4 which is provided for and through which the spindle S extends inoperative association with the latch bolt unit L. The forward, outer endof unit L is provided with a vertically disposed face plate I'I attachedto a back plate I secured on the forward end of the case of the unit L.Unit L is mounted in position in opening 2 in the usual manner byattaching the plates I05 and I0'I to the door edge by screws I0Ia, asshown in Fig. 2.

The spindle S is formed in this instance of square cross section (seeFig. 2) and is primarily supported in the example hereof in itshorizontally disposed position at the central or intermediate portionthereof which extends through and is received in the latch bolt unit Lin operative connection with the latch bolt retracting mechanismtherein. The spindle S mounts at its opposite ends and the oppositesides of door D. The inner and outer door knobs I and 0, respectively,which are connected therewith in the usual or any desired manner topermit of the spindle S being rotated thereby in either direction bymanual turning of either of the knobs. Any suitable outside rose I4 maybe provided at the outer side of the door through which spindle Srotatably extends, and similarly a suitable inside rose I5 may beprovided at the inner side of the door through which the spindle extendsfor rotation therein.

The latch bolt unit L of the example embodiment of my inventioncomprises a case I00 which may be stamped, pressed or otherwise formedfrom a suitable sheet material to include a side wall IOI, oppositeedge, parallel walls I02 and I03 connected at one end by an end wallI04. In this instance the wall I02 is shown as the upper wall while wallI03 is the lower one and the wall I04 is the inner end wall of the casewith the unit L in installed position in the door D. At the forward endthereof the case I00 is open and the walls I02 and I03 have at theirouter end edges the upwardly and downwardly turned tongues mm and I03a,respectively, by which the case I00 has secured and attached to theforward or outer end thereof the vertically disposed back plate I05.This plate I05 is provided with a central opening I06 therethrough whichwith the plate in assembled position on the forward end of case I00 isaligned with the open forward end of the case. The complementary faceplate I01 is suitably secured on and covering the outer side of theinner or back plate I05. The face plate I0! is provided with arectangular opening I 08 therethrough which is aligned with the openingI 06 in the back plate I05. The aligned openings I06 and I08 in theplates I05 and I0'I are adapted to slidably receive therein the usualdoor latch bolt 99 for retraction and projection therethrough in theoperation of the latch bolt unit L.

Case I00 is completed by the attachment thereto of a cap I09 which formsthe side wall of the case opposite and parallel with the side wall IOI.The cap I09 at its forward end is provided with a forwardly extendedtongue I09a by which it is secured to the back plate I05 and face plateI01 in the assembled position of the case. The rear end of the cap I09is formed with a recess I09b adapted to receive therein a tongue I04aformed on and projecting from the free edge of the inner end wall I04.The tongue I04a fitted into the recess I091) attaches and positions therear end of the cap I09 on the case I00 in assembled position thereof.The top wall I02 and the bottom wall I03 are each formed of reducedwidth intermediate their forward and rear ends to provide the elongated,longitudinal seating edges I 02b and I 03b, respectively. The walls I02and I03 at their forward ends at the open side of the case whichreceives the cap I09 thereover, are formed to provide the projectingtongues I020 and I03c, respectively. Seats I 02d and I03d are thusformed by the edges of the walls I02 and I 03, respectively, whichconnect the tongues I020 and I03c with the elongated seat forming edgesI02b and I03b. The walls I02 and I03 are provided with cut-outs H0therein which are aligned transversely of the case I00 in positionslocated intermediate the seating edges I02b and N31) and the inner endwall I 04. Transversely parallel tabs I022 are formed from the walls I02 and I03 between the cut-outs H0 and the inner ends of seating edgesI02b and I03b, while at the rear sides of the cutouts IIO, Walls I02 andI03 are formed to provide the outwardly projecting tabs or tongues I027,respectively.

The cut-outs or recesses H0 in the walls I02 and I03 provide the similartransversely aligned seats IIOa, which seats are extended inwardly andforwardly by undercuts or re-entrant recesses to form in the walls theforwardly extended slots IIOb. The wall IOI and the cap I09 of case I 00are formed with the circular openings III transversely therethroughrespectively, which with the unit in assembled relation are axiallyaligned for receiving therethrough the latch bolt actuating spindle S.

The case side wall forming cap I09 is formed with the laterally offset,longitudinal edge flanges I 09c and the laterally offset transverseinner end flange I09d, in which latter flange the recess I091) isprovided. The flanges I 090 terminate spaced from the forward end of thecap I09 and the cap is formed intermediate its forward end and theforward ends of flanges [099 with the opposite side, laterally extendingtongues I09e and the opposite forward recesses I09 The offsetlongitudinal flanges I050 of the cap I09 are formed with the pairs ofopposite transversely aligned recesses I09g in locations for receivingtherein the pairs of case tongues I02e and I02 respectively.

In assembled position of the cap I09 on the case I00, tongues I02c andI030 seat in the cap recesses I09f; cap tongues I09e seat on the caseseats W211 and IBM; the offset flanges I090 of the cap I09 seat on theelongated longitudinal edge seats I02b and I03b of the case walls I02and I03, and extend rearwardly over and across the cut-out portionswhich form the inset seats IIOa; the case tongues I02e and I02 are received in the cap recesses I09a, respectively, and case tongue IMa isreceived and seats in the recess I09b of the offset end flange I09d ofthe cap I09. The tab or tongue I 09a projecting from the forward end ofthe cap I09 extends through the opening I06 of the back plate I05, beingengaged over the adjacent edge portion of that opening, while thetongues I02a and Ba of the case I00 also extend into back plate openingI05 5 and are engaged over adjacent edge portions of that opening.

The case closing cap I09 thus has in effect a snap attachment on and tothe case I in assembled position thereof, so that it may be readilyassembled on the case with the case assembled in attached position tothe back plate I at the forward end thereof. The tab or tongue I04a mayafter assembly be bent slightly inwardly over and engaged with the capto insure against cap displacement. It may be as readily bent outwardlysufiiciently to enable ready detachment and removal of the cap I09 fromthe case I00 in the event that it should become desirable to open thecase for repair or replacement of any of the parts of the latch boltmechanism contained within the case. The complete case itself comprisesbut two (2) readily manufactured major components, namely, the case I00and the cap I09, while the latch bolt receiving and mounting structureattached to the forward end of the case I00 comprises but two (2) parts,namely, the back plate I05 and the face plate I 0'! which are easilymanufactured and readily assembled on the forward end of the case.

The mechanism for retracting and projecting the latch bolt 99 is mountedand enclosed within the case I00 and cap I09, and in accordance with myinvention such mechanism includes a a hub or roll-back mounting, bearingmember II2. This bearing member H2 is provided with a circular boretherethrough and is mounted on the spaced seats I Illa provided by thecut-outs H0 in walls I02 and I 03, with such bearing member in positionextending across the case I 00 between the wall I0! and the cap I09 withthe bore H3 thereof axially aligned with the bores H0 in case wall IOIand in the cap I00. The bearing member H2 is formed with the oppositeextended portions forming the flanges II2a which engage and seat uponthe seats I I0 and at their forward ends are received and engaged in theslots formed by the undercuts IIOb respectively, in the walls I02 andI03. The bearing member H2 is formed or provided with the inwardlyturned flange II I across the forward end thereof. This flange I I4 isformed curved or arcuate about the axis of the bore I I3 as a center.The effective length of this flange H4 is equal to the spacing betweenthe inner surfaces of the walls I02 and I03, so that the flange will fitinto position therebetween. A hub or roll-back member H5 having a squareopening I I 6 therethrough which is dimensioned to slida'bly fit andreceive therethrough the spindle S, is provided for rotatable mountingon and against the inner side of the bearing member II2. Hub member H5is formed to provide the curved forward edge II1 complementary with theinner curved side of the arcuate flange H4 for slid-able bearingengagement with such flange. The curved forward edge II! of rollbackmember II5 has its opposite ends extended outwardly beyond the body ofthe roll-back member to form the upper and lower lugs H8.

A yoke member I 20 of generally elongated, rectangular form is slidablymounted and confined within the case it!) for actuation by rotation ofthe roll-back I 15 to retract and project the latch bolt 99. This yokeI20 includes a vertically disposed wali iZI having an elongated openingI22 transversely therethrough with this wall in assembled position ofthe yoke in the unit disposed and slidable between the inner side ofrollback member H5 and the outerside wall or cap I 09, as will be clearby reference to Fig. 1. At its forward, upper side the yoke I20 has aninwardly bent guide and positioning finger I23 which has slidableengagement at its free end with the inner side of case wall I0 I. At itsforward, lower side the yoke I20 is formed with an inturned flange I 2%which also has at its inner free end, slidable bearing engagement withthe inner side of the wall IOI of the case I00. The flange I26 is formedwith a rectangular openin I25 therethrough. The yoke I20 bridges theroll-back member H5 and the spindle S whichextends therethrough inassembled position, and at its rear end between the bearing member IE2and the inner end wall I04 of the case I00, th yoke is bent inwardly forits full Width to form the flange I26 thereacross which has slidablebearing engagement with the inner surface of the wall IOI, and whichtogether with the finger I23 and the flange I24 at the forward end ofthe yoke, provides the positioning and aligning support for thereciproctaion of the yoke within the case I00. The yoke I20 has lateralguiding support in the direction of the cap I09 by slidable engagementwith the inner side, fiat surfaces provided by the portions of the capcontiguous thereto.

The yoke member I20 has formed and bent-up therefrom at the upper andlower side edges of the wall I21, the upwardly and downwardly projectedears I30, respectively. The ears I30 are located on the wall I2Iintermediate the length of the elongated opening I22 and in positions atthe rear of and engaged by the upper and lower lugs I18, respectively,of the roll-back member H5. Hence, in assembled position the rotation ofthe roll-back member H5 in either direction by rotation of the spindle Swill cause the rearwardly swinging or rocking lug I I8 to engage itsyoke mounted ear and to thereby force or slide the yoke rearwardly inthe case I 00 in a direction to retract the latch bolt 99.

The latch bolt 99 of the latch bolt unit L may be considered to be ofgenerally conventional design to provide the usual inclined face orsurface for slidable engagement against the strike plate 8i (see Fig. l)of a door frame. In this instance, the latch bolt 99 is slidabiypositioned in and guided by the square opening I08 through the faceplate I07, and extended inwardly through the opening I06 of the backplate I05 which is attached to the forward end of the case I80. Thelatch bolt 99 has suitably connected to the end thereof a tail pieceIv'iI which extends inwardly a distance into the case I20 and which isprovided at its inner end with an upwardly projected nose forming a hookI32. The hooked inner end of the tail piece IEI extends into therectangular opening I 25 of flange I2 1 of the yoke I20 in position withthe upwardly extended nose of the hook I32 engageable against the innerside of the flange I24 at the upper side of the opening I25. Uponrearward movement of the yoke I20 within the case i00 the hooked innerend H32 of the tail piece I3I being engaged with the yoke will draw thetail piece rearwardly and retract the latch bolt 99. However, the latchbolt 53.; with the tail piece I3I is movable rearwardly relative to andindependently: of the yoke I20 by rearwardly acting forces-applied tothe latch bolt at the outer end thereof. Under such conditions the tailpiece I3I slides freely rearwardly through 7 and over the tail piece 431under compresison between the 'rear of'the latch bolt 99 and the flange12! of the --yokemember 128. Thus, thelatch bolt when depressed or movedinwardly relative to th yoke l2il places the spring i33 under increasedcompression, so that upon release of the inwardly acting forces on thelatch bolt the latter is instantly projected outwardly to normalstrike-engaging, door latching position.

The yoke member I20 is spring loaded and normally continuously biased toits forwardly prodesired position. With the unit L of my presentinvention the spring loading of the yoke I'Z'O is provided by a coiledexpansion spring I34 which is inserted under compression within the casel 90 between the inner end wall I01 of the case and the inner end flange126 of the yoke I29. When the roll-back 115 is rotated in eitherdirection by spindle :S which extends transversely therethrough indriving connection therewith in assembled position, the "yoke 2 8 isforced rear- 'wardly against the spring 434 and the latch bolt isretracted. Upon release of the turning forces on the spindle S thespring 134 acts to instantly move the yoke I20 forwardly to return it tonormal, latch bolt projected position. When the latch bolt 39 isretracted by rearward movement of the yoke 12!! against the spring ltd,the spring 133 is not further compressed. However, when the latch bolt98 is depressed and retracted independently of the yoke I20, the springI33 is compressed and in order to permit of such compression spring I34must not yield to the forces applied to the yoke by the spring I33.Hence, spring 134 is formed heavier to exert a force greater than thatof the-spring 133, so as to be unyielding under such conditions.

By the foregoing design, construction and assembly I have produced adoor latch bolt unit of extreme mechanical simplicity with a minimum ofparts each of which may be readily manufactured by low-cost quantityproduction and which parts lend themselves to ready, time assembly withassurance of proper operative relation of the parts when assembled. Withthe twopart pressed or stamped case a light-weight structure is producedwith close tolerances and without the need for expensive finishingoperations. The case structure with its snap-on cover plate is readilyassembled and disassembled, while providing an exteriorly clean case.The design and assembly of the case with the bearing plate mountingprovided therefor, not only makes for ease of assembly but insures in aminimum friction and wear arrangement when assembled in operativerelation in the case with the roll-back and the latch bolt retractingyoke.

It will also be evident to those skilled in the art that variouschanges, variations, modifications, substitutions, eliminations andadditions might be resorted to without departing from the broad spiritand scope of my invention, and hence I do not intend or desire to limitmy invention in all respects to the exact and specific disclosureshereof, except as may be required by intended specific limitationsthereto appearing in any of the appended claims.

What I claim is:

1. In a tubular latch bolt unit, in combination, a tubular caseincluding spaced opposite edge walls and a side wall connecting saidedge walls at one side thereof, said case being open at the side thereofopposite said side wall, said opposite edge walls being formed withtransversely aligned cut-outs therein opening through the free edges"thereof, respectively, to provide "inset seats, a

bearing plate member mounted on said seats in position extending acrossand between said edge walls within the case intermediate said sidewalland the opposite open side of said case, said bearing plate member beingformed with a bore'tra'nsversely therethrough and being provided at oneedge thereof transversely ofsaid case with an inwardly extended arcuateflange, a rollfback mounted in position against the inner "side of saidbearing plate member, said roll-back having "an arcuate edge in slidablebearing engagement with said arcuate flange of said bearing platemember, said roll-back being adapted for rotation about the axis of saidbearing plate member bore, and a closure cap attached to said case overand 010sing the open side thereof in position spaced from said roll-backwhen the latter is in operative mounted position on said bearing platemember.

2. In a tubular latch bolt unit, in combination, a case formed toprovide a side wall, spaced opposite edge walls and an end wall closingone end of the case, the opposite end of the case and the side thereofopposite said side wall each being open, said opposite edge walls eachbeing of reduced width along intermediate portions thereof to formelongated inset seating edges therealong, each of said edge walls beingprovided with a cut-out therein to provide an inset seat intermediatesaid end wall and the adjacent end of said reduced width portion of theedge wall, tongues on each of said edge walls projecting outwardly fromthe free edge thereof at locations thereon intermediate said end walland said inset seat at one end of the case and at the opposite endthereof intermediate said open end and the adjacent end of the reducedwidth portion of said edge wall, a bearing plate member mounted on saidinset seats in position extending transversely through said case betweensaid edge walls and intermediate said side wall and the opposite side ofsaid case, a cap member mounted in position seated on said elongatedseating edges of said edge walls over and closing the open side of saidcase spaced from said bearing plate member, and said cap member beingformed with seats formed in the edges thereof adapted to be engaged bysaid tongues, respectively, to maintain said cap in position on andclosing said case.

3. In a latch bolt unit, in combination; a tubular case including spacedopposite edge walls each having a portion thereof cut-out inwardlythrough an edge of the wall to provide therein an inset edge disposedlongitudinally of the wall intermediate the opposite side edges thereofto form an inset seat; said seat forming edges being alignedtransversely of said case and ends of said edges being extended byundercuts in said walls, respectively, to form retaining slots intowhich said seats extend; and a substantially flat bearing plate membermounted on said seats and received in said retaining slots in positionextending across said case between said opposite edge walls.

4. In a tubular latch bolt unit, in combination; a case providing a sidewall, an end wall, and spaced opposite edge walls to form a case open atone side and at one end thereof; said opposite edge walls being providedwith recesses forming inset seats therein, respectively, alignedtransversely of said case intermediate the open side and said side wallof the case; a bearing plate member mounted on said transversely alignedseats in position extending transversely through the interior of saidcase between said opposite edge walls and spaced from said side wall andof said-platemembenfacingthe open sideof said case; said flange at theinner side thereof facing said plate -member bore -being .formed toprovide an arcuate bearing surface having the axis of said 'bore as acenter; a 'rollback rotatably mounted in 'bea-ring engagementagainst theside of said bearing plate *member facing the open side i of said casefor rotation about the axis of said bore; the e'dge ofsaidrollback-adjacent said bearing plate member flangebeing; provided withan arcuate bearing surface -complementary to and in bearingengagementwith the arcuate bearing surface of said flange; and a 3 plate-likeclosure cap attached to said case over and --closi-ng the open sidethereof rsaid rollbaok and" said'closure cap being formed inassembled"positions-thereof to form a spacetherebetween within saidcase.

-5. In atubular latch bolt unit, in combination; a tubular caseincluding spaced opposite side walls-end spaced opposite.- edge swalls,said case in closedatone endebyan endwalland being open at the oppositeend; a bearing plate member mounted at oppositeaedge portions thereofon-said opposite iedgeiwalls, respectively, in positionextendingntherebetween through said' case intermediate and spaced fromsaid opposite side walls; a rollback rotatably mounted in position inbearing engagement against one side of said bearing plate member forrotation thereon about an axis transverse of the plane of said bearingplate member; a yoke member reciprocably mounted in said case betweensaid roll-back and the adjacent side wall of said case; said yoke memberat its opposite ends having laterally inwardly projected flanges insliding bearing engagement at their outer ends at opposite sides,respectively, of said bearing plate member with the adjacent side wallof said case; said yoke member at the end thereof adjacent the open endof said case having an end wall formed with an opening therethroughadapted to receive therein a latch bolt; and an expansion spring looselymounted in the space between said end wall of the case and said flangeon the adjacent end of said yoke and being confined under compressionbetween said end wall and such flange.

6. In a latch bolt unit, in combination, a tubular case formed with oneside wall, one end wall. and opposite edge walls to form a case open atone side and at one end thereof, and a plate-like closure cap fittedover said open side to close said case; said opposite edge walls beingprovided with cut-out portions therein opening through the side edgesthereof to form transversely aligned edges disposed longitudinally ofsaid case providing seats spaced inwardly thereof from and intermediatesaid side wall and said closure cap; the adjacent ends of said edges ofsaid cut-out portions being extended inwardly by undercuts in said edgewalls, respectively, to provide retaining slots therein; a substantiallyflat bearing plate member having planar opposite side surfaces, saidbearing plate member being engaged at its opposite ends on said edgewall seats in position extending across said case between said oppositeedge walls and intermediate and spaced from said side wall and saidclosure cap; said bearing plate member being provided with portionsthereof extending into said retaining slots to secure said bearing platememberlinimountedposition said case; said bearing plate memberhavingaibore transversely therethrough; "and a rollback member mountedinposition at one;sideoflsaidbearing plate meniber in bearing engagementwith the planar surface :thereof for rotation about-the axis of saidbore in said :bearing-plate member. r :7. :Ina latch bolt unit, incombination; a tubular case including spaced opposite walls; said wallsbeing formed to "provide" seats therein aligned transversely-of saidcase; abearing'plate .member-mounted on said seats in position extendingtransversely of said case through the interior thereof betweeri andintermediate the ,oppositeedges-of saidspaced walls; said-bearing.plate-membierzhaving "a boretherethroug'h and being formed acrossoneend thereof with a; guide flange provided at the-inner'side thereoffacing said plate memberibore with an arcuate bearing surface generatedaboutthe axis of said bore as aacenterisa rollback me nber'atone side ofsaid bearing (plate member .mounted for rotation about: the axis ofsaidbore inbearing engagenent against theadjacent side of said bearingplate, member; i and-said rollback being "formed with an arcuatebearing-surface thereon in bearing engagement with the arcuate bearingsurface ofsaid guide flange.

L8. In a .latch' bolt mechanism, in combination; a tubular caseincluding spaced opposite walls; said walls being formed to provideseats therein aligned transversely of said case; a bearing plate membermounted on said seats in position extending through the interior of saidcase between and transversely of said spaced walls and having acentrally located bore transversely therethrough; said bearing platemember having one edge portion thereof formed to provide an arcuateflange extending laterally of said plate member from one side thereofspaced from and being generated about the aXis of said bore as a center;and a rollback member mounted for rotation at and in bearing engagementagainst the side of said bearing plate member from which said arcuateflange extends; and said rollback being mounted for rotation about theaxis of said bore and the edge thereof adjacent said arcuate flangebeing formed for bearing engagement thereon.

9. In a tubular latch bolt unit, in combination; a. tubular caseincluding a side wall and spaced opposite edge walls with the side ofsaid case opposite said side walls being open; said opposite edge wallshaving cut-outs therein providing inset edges forming seats in said edgewalls, respectively, aligned transversely of said case; a closure capmember attached to said case over and closing the open side thereof; asubstantially flat bearing plate member mounted on said inset seats insaid edge walls in position extending across and bridging said casetherewithin between said edge walls intermediate but spaced from bothsaid side wall and said closure cap member; said bearing plate memberhaving a bore transversely therethrough and being formed to provide asubstantially planar bearing surface at the side thereof facing andspaced from said closure cap member; and a rollback member mounted atthe side of said bearing plate member facing said closure plate memberfor rotation about the axis of said bore through said bearing platemember in bearing engagement with said planar bearing surface thereof.

10. In a latch bolt mechanism, in combination; a tubular case includingspaced opposite walls; a substantially flat bearing plate member mountedin position extending through the interior of said case between saidspaced walls intermediate the opposite edges thereof; said bearing platemember having a bore transversely therethrough and having one edgethereof formed to provide an arcuate flange extending laterally of saidplate member from one side thereof spaced from and being generated aboutthe axis of said bore as a center; a substantially flat, plate-likerollback member mounted in position in said case for rotation at and inbearing engagement against the side of said bearing plate member fromwhich said arcuate flange extends;

and said rollback member at the edge portion thereof adjacent saidarcuate flange being formed to provide an arcuate surface for bearingengagement on said arcuate flange.

11. In a tubular latch bolt unit, in combination; a tubular caseincluding spaced opposite side walls and spaced opposite edge walls; asubstantially flat bearing plate member mounted at opposite edgeportions thereof on said opposite edge walls, respectively, in positionextending therebetween through said case intermediate and spaced fromsaid opposite side walls; said bearing plate member having a boretransversely therethrough; a substantially flat rollback memberrotatably mounted in position for bearing engagement against one side ofsaid bearing plate member for rotation thereon about the axis of saidbore in said bearing plate member and being spaced from the adjacent ofsaid opposite side walls of said case; said rollback member having abore therethrough for axial alignment with said bearing plate memberbore; a yoke member reciprocably mounted in said case across and betweensaid rollback and the adjacent side wall of said case adapted to retainsaid rollback against displacement laterally from position at saidbearing plate member; and said yoke member being provided with anelongated slot therethrough opposite and aligned with said alignedrollback member and bearing plate member bores and at its opposite endshaving lateral inwardly projecting flanges in sliding bearing engagementat their outer ends with the adjacent wall of said case at oppositesides, respectively, of said bearing plate member.

GOTTHARD HAGSTROM.

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date 2,390,756 'Voight Dec. 11, 1945 2,486,268 Erkkila Oct. 25,1949

